Theoretical Study For Emission Of Prescission Particle Of Heavier Nuclei With Pathwise Analysis Method

In this paper, we make a brief review about the history of nuclear physics. Then we introduce the concept of radioactive nuclear beam and exotic nuclei. The main introduce is made to the three stage theory of nuclear reaction, and the theory of fission dynamics, namely the FPE equation and LE equation. In addition, we also introduce the nuclear dissipation which delays the nuclear fission, and its probe, nuclear dissipation. Next, we describe detailed two kinds of models which make calculate with in this work, the combined dynamics and statistical model (CDSM) and its modified version model (MCDSM). Furthermore, the pathwise analysis method is introdued, which is a new theoretical method to analyze the calculation results.The emissions of prescission particles in the deexcitation process of Au isotopes,191,194,197Au are investigated deeply in the core part of the work. The isotope effection of prescission neutron is:the greater N/Z ratio nuclide have more prescission neutrons. These cifferences mainly comes from the process of the ground state to the saddle point. Prescission protons and alpha particles’ multiplicity is gradually stronger along weith the chandg of energy, without weakening range. Prescission protons and alpha particles’ multiplicity is independ on nuclear dissipation, for performance CDSM is more powerful in the process of the ground state to the saddle point; the difference from the saddle point to the breakpointphase difference is little.To sdudy the barrier correction effect on prescission particle emission the fusion has a lower effective barrier, so from the average effect, we introduce the barrier correction factor, to recalculate the Au isotope thermonuclear prescission particle multiplicity, using pathwise analysis method to study the reduced barrier influence on prescission particle emission. Found that barrier correction have less effect on prescission neutron multiplicity. Through the stdudy of proton and alpha particle, fire barrier influence the prescission charged particle multiplicity is in the regular changes. And change is more obvious. Emission barrier correction doesn’t change the isotope effect of prescission neutron.